Submarine dredge



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SUBMARINE DREDGE Filed Dec. 31, 1963 5 Sheets-Sheet 1 INVENTQRS [7%9513MKS 0x219,

Henry; Prekm I ATTO NEYS March 2, 1%? E- w. SPANNHAKE ETAL 3,31%

SUBMARINE DREDGE ATTORNEYS Mmdh 3%? E. w. SPANNHAKE ETAL 3,

SUBMARINE DREDGE Filed Dec. 51, 1963 5 Sheets-Sheet 4 ATTORNEY 6SUBMARINE DREDGE 5 Sheets-Sheet 5 Filed Dec. 31, 1963 INVENTORS mm fi mP fiw n 3,310,892 SUBMARINE DREDGE Ernest W. Spannhake, KinnelonBorough, N.J., and Henri Prehn, Roslyn Heights, N .Y., assignors to JohnJ. McMullen Associates, Inc, New York, N.Y., a corporation of New YorkFiled Dec. 31, 1963, Ser. No. 334,740 Claims. (Cl. 37-56) The presentinvention relates to submerged vessels such as submarine dredges.

Basically, a submarine dredge is a submersible vessel for digging atrench along the bottom of a body of water. In one form, the dredge ismanned by personnel while it is submerged and consequently, access toand from the submerged dredge becomes a special problem.

In one type of submarine dredge that has been proposed, access to thedredge is achieved by a pressure chamber (similar to a submarine rescuechamber) which plies between a floating power supply vessel and thedredge. In bad weather, access to and from the dredge is awkward andrisky. Moreover, the power supply vessel must be anchored in thevicinity of the dredge, and this requirement is a handicap.

In another type of submarine dredge, access to the dredge is achievedthrough a hollow tower which is rigidly attached to the dredge andextends vertically to a landing deck at the top of the tower above thewater. The operation of this type of dredge is limited to a body ofwater that does not vary greatly in depth.

It is an object of the present invention to provide improved means fortransferring either personnel or supplies to a submerged vessel.

Another object is to provide an improved submarine dredge that can besafely manned and operated underwater even if the weather is bad, thebody of water is very rough, and the water varies greatly in depth.

A further object is to provide an improved submarine dredge that doesnot require the presence of a nearby power supply vessel to operate thedredge.

Still another object is to provide a submarine dredge that is moreeflicient than submarine dredges heretofore. known in the art.

The foregoing objects are achieved by a submarine vessel which has asnorkel tube extending therefrom. One end of the snorkel tube isattached to the vessel by a universal joint. When the vessel issubmerged in a body of water, the other end of the snorkel tube isfree-floating at the surface of the water. The snorkel tube houses:means for transferring personnel to and from the submerged vessel; airintake and exhaust space; and spaces for supplying fuel and services tothe vessel.

With the vessel submerged in a body of water and the upper end of thesnorkel tube free-floating, the tube is at an inclined angle withrespect to the surface of the water. At a point just below the watersurface, the snorkel tube is bent so that it projects upward in anapproximately vertical direction. The lower part of the upper portion ofthe snorkel tube is fitted with nonbuoyant streamlined plate covers tominimize wave slap. For transferring personnel and landing supplies forthe dredge, a landing cage having three platforms is pivotally carriedby the upper portion of the snorkel tube. In addition, a crane iscarried by the snorkel tube for transferring supplies and spare andrepair parts to the dredge.

In the drawings:

FIGURE 1 is a perspective view of a submarine dredge provided inaccordance with a preferred embodiment of the present invention, thedredge body being illustrated in submerged position for digging a trenchalong the bottom of a body of water;

nitecl States Patent C) 331,892 Fatented Mar. 28, 1967 ice FIGURE 2 is aview of the front end of the dredge body, but shows the snorkel tubebroken off just above the universal connection to the dredge body;

FIGURE 3 is a perspective view of the upper portion of the snorkel tube;

FIGURE 4 is a sectional view of the upper portion of the snorkel tube,and is taken along the line 44 in FIG- URE 3;

FIGURE 5 is a sectional view of the lower end of the snorkel tube anduniversal joint connection to the submarine dredge and illustratingaccess to the dredge;

FIGURE 6 is a vertical sectional view illustrating the access door inthe upper end of the snorkel tube above the water communicating with theplatform; and

FIGURE 7 is a sectional view taken along lines 77 of FIGURE 6illustrating the upper portion of the snorkel tube adjacent the platformand means for running the power and water lines therethrough adjacentthe platform access door.

Referring to FIGURE 1, the submarine dredge comprises a hollowcylindrical body 11, a hollow snorkel tube 12, four tractor drive means13 for propelling the dredge, and trenching equipment 16 for digging afurrow 17 at the bottom of a body of water having a surface 18. A pairof exhaust tubes 21 and 22 extend laterally from respective ends of thebody 11 for disposing mud, silt, etc. that has been dug up by thetrenching equipment.

The hollow cylindrical body 11 contains a pair of end sections 25 and 26for ballasting the dredge. An intermediate section 27 houses: a dredgecrew; controls; and diesel machinery for powering the tractor drivemeans 13 and other elements of the dredge that use power. The spreadbetween the tractor drive means at opposite ends of the dredge body 11is sufficiently large to stabilize the dredge body 11 against moments offorce applied to the body by the snorkel tube 12.

The snorkel tube 12 extends from the body 11 along an incline relativeto the water surface 18. The upper end of the tube 12 is free-floatingabove the water. The lower end of the tube 12 is connected to the centerof the body 11 by a hollow universal joint 30. The snorkel tube 12permits the dredge to breathe underwater.

At a point which is slightly below the water level 18, the snorkel tube12 has a curved portion 31 which turns into an upper portion 32. Portion32 extends out of the water in an approximately vertical direction. Ifthe lower portion of the snorkel tube 12 has an assumed maximum angle offorty-five degrees inclination relative to the water surface 13 for amaximum operating depth of the dredge body 11, the upper portion 32extends vertically approximately thirty-five feet above the watersurface 18, for example. The top of the upper portion 32 is well abovethe crest of the highest wave.

The snorkel tube 12 has an outside diameter of approximately seven andone-half feet, for example. As is shown in FIGURE 4, the tube 12contains divisions which form a rectangular housing 33 for a movableelevator cage 34 to transport personnel and supplies through the snorkeltube and the universal joint 30 to the hollow body 11 of the dredge. Thethroat of the curved portion 31 of the snorkel tube 12 is widened topermit easy run of the elevator cage 34.

At opposite sides of the housing 33, two spaces 35 and 36 are used forair intake and exhaust, respectively, for the hollow dredge body 11. Theair intake supplies fresh air to the diesel machinery and also is usedfor ventilation. Exhaust from the diesel machinery passes through thespace 36.

At the other opposite sides of the housing 33, two spaces 37 and 40 areprovided, respectively. The space 37 is used for housing fuel supplylines or pipes, which are connected to the diesel machinery within thedredge body 11. The space 40 is used for housing lines or pipes tosupply fresh water and electric power services.

The top of the upper portion 32 of the snorkel tube 12 is decked over,except for the openings for air intakes, exhausts, and the endconnections of the pipes for supplying fuel and services. A watertighthatch 41 is fitted for access to the elevator cage 34. In addition, acrane 42 of approximately three ton capacity, for example, is fitted tothe upper portion 32 of the snorkel tube for transferring spare andrepair parts to the dredge by means of the elevator cage 34. The airexhaust space 35 is provided with a projecting stack above the top oftube 12 to prevent contamination of intake air.

As is shown in FIGURE 3, a landing cage 45 is pivoted to a pair of largesupport brackets 46. These brackets are rigidly attached to the upperportion 32 of the snorkel tube 12. A suitable bufier means, not shown,is employed between the cage 45 and the snorkel tube upper portion 32 tokeep the cage from banging portion 32 as the cage sWings about an axisthrough the brackets 46.

The landing cage 45 has three platforms at different levels fortransferring personnel and landing supplies to be transported by theelevator cage 34 to the hollow dredge body 11. Access to the air intakeside of the snorkel tube upper portion 32 from the top platform of thelanding cage 45 is accomplished by a watertight door 59 and by a movableramp 47.

Referring to FIGURES 6 and 7 the ramp 47 extends into the upper portion32 of the snorkel adjacent the forward end of the elevator cage 34. Theinlet area adjacent the door 50 is provided with vertical partitions 54and horizontal partitions 55 extending between the periphcry of the tubeand the vertical front wall or partition 56 of elevator cage housing 33to form a space or an inlet chamber 40a between the platform and theelevator cage. The water pipe 57 and power lines or cables 58 extendthrough the restricted or reduced passages 59 defined by partitions 54,56 and the tube and do not interfere with access to the elevator cagefrom the platform.

The lower end of the tube 12 is connected to the dredge 11 by universaljoint means generally indicated as 30 and best illustrated in FIGURE 5.Tube 12 is provided adjacent its lower end with yoke means including twodivided and separated tubes or leg members 62. The hollow members 62extend downwardly and outwardly from the lower single tube portion 12and have a substantially lateral portion 63 joining their upper innerends together. The portion 63 serves as the lower end of the elevatorshaft and cage 34 rests thereon, as shown in FIGURE when it is in itslowermost position. One tube 62 is provided with a series of steps,guard rails and platforms or landings indicated generally as 64- topermit access of personnel to and from the dredge 11. The lower end ofthe water pipes 57 and power cables 58 also extend through this leg anddown into the dredge proper.

The other leg or tube 62 is provided with an air intake conduit 65 andair exhaust conduit 65a in communication at their lower ends with theinterior of dredge 11, and at their upper ends with their respective airintake and exhaust passages, spaces or stacks 35 and 36.

Each leg 62 is provided with an inwardly and laterally extending hollowtubular section or member 66 as shown in FIGURE 5. The lateral legs 66are provided with bearings 67 and wedge type sealing rings or stufiingglands 68 to provide a watertight seal with a T joint member 69. Thebearings permit the legs 62 and snorkel tube 12 to rotate or pivot aboutand with respect to T member 69.

The T member 69 has a vertical leg 70 which is preferably ten feet indiameter mounted in bearings 71 to permit it to rotate or pivot aboutand with respect to the vertical tube or chamber '72 communicating withthe interior of the dredge 11 and fixed by welding or the like thereto.The tube 72 is provided with proper sealing rings and gland means 74 toform a watertight joint. The

stufiing seal glands may be of a well known type used on ships whereinthe propeller shaft extends through the hull, and be of a bleed typewherein water under pressure is continuously forced in an outwarddirection out of the hull, or in the present case out of the tubemembers.

As illustrated in FIGURES l and 3, a non-buoyant, streamlined pair ofbowed plates 51 and 52 are fitted around the snorkel tube upper portion32. The plates 51 and 52 are joined at their ends to form narrow foreand aft edges on opposite sides of the portion 32 for minimizlng waveslap. The plates 51 and 52 extend from about five feet below to ten feetabove the surface 18 of the water.

With the bottom end of the snorkel tube 12 held down by the universalconnection to the submerged dredge body 11, the snorkel tube finds itsown level when the moment of snorkel buoyancy equals the moment of itsown weight about the universal joint 30. The upper end portion 32 of thesnorkel tube 12 provides reserve buoyancy. In one design for the snorkeltube 12, at a maximum submerged depth for the dredge body 11 the snorkeltube 12 is inclined at an angle of forty-five degrees at a moment whenbalance is achieved between buoyancy and snorkel tube weight. Through arange of different water depths resulting in varying inclinations of themain snorkel body, the top end of the snorkel tube always floats closeto the same waterline with buoyancy and weight moments balancing out.

If the dredge is operated through a range of water depths where thelower end of the snorkel tube 12 (at the universal joint 30) changes indepth from a maximum of one hundred fifty feet to a minimum of thirtyfeet, for example, the top of the snorkel tube upper portion 32 movesfrom thirty-five feet above water for the maximum depth to approximatelytwenty-nine feet above water for the minimum depth. The upper portion 32makes a corresponding change from its vertical position to a positionthat is inclined by approximately thirty degrees with respect to thevertical.

Through the universal joint 30, the snorkel tube 12 will turn into aposition where no turning moment is exerted on the dredge body 11. Inother words, the snorkel tube 12 always assumes a position of leastresistance in line with wind and wave and/or current.

The diameter of the snorkel tube 12 is relatively small. Therefore, thetube 12 offers a minimum resistance to the current in the body orchannel of water. The streamlined plates 51 and 52 about the waterlineof the upper portion 32 of the snorkel tube 12 minimize the resistanceof the snorkel tube 12 against wind and wave slap. Furthermore, becauseof the relatively small diameter of the snorkel tube 12, change ofincline of the tube due to wave action will be minor.

The dredge body 11 must be weighted down sufiiciently to overcome dredgeupsetting forces at the universal joint 30 which are caused by current,wind and waves acting upon the snorkel tube 12. If the bottom of thebody of water in which the dredge is to operate is too soft for therequired dredge weight, the dredge trenching equipment can be modifiedto cover a few feet on each side of the tractor drive means 13 atopposite ends of the dredge body 11. Top layers of soft bottom would bedredged away in front of the dredge tracks. Therefore, the weight or thebearing pressure of the dredge can be considerable without bogging downthe dredge.

In operation of the dredge, personnel are landed on one of the platformsof the landing cage 45 by a boat, not shown, which can leave thedredging area without interrupting the operation of the dredge. Thepersonnel pass through the door 50 in the snorkel tube upper portion 32,close the door, and are transported to the dredge body 11 by theelevator cage 34.

The diesel machinery is manned and controlled by the personnel to powerthe tractors 13 for propelling the dredge body 11 along the bottom ofthe water. As the dredge is propelled, the trenching equipment 16 digs adeep furrow 17. As the furrow is dug, mud and silt is disposed oflaterally from the dredge body 11 by the tubes 21. The dredge isoperated safely and efficiently even though the weather above watermight be extremely bad, the body of water might be very rough, or thewater might vary greatly in depth. Moreover, no floating power supplyvessel is required to be anchored in the vicinity of the dredge.

The dredge equipment is preferably diesel hydraulic with a revolvingcutter.

The dredge will be steered by a sonar beacon system, where a hydrophoneis mounted at each side of the dredge, receiving signals from a sonarbuoy. From the difference in time between receipt of the sound wave ateach hydrophone, the angle of deviation between the vehicles directionof travel and the bearing to the sonar beacon can be calculated. When oncourse there is no time difference, and the vehicle is heading for thebeacon.

Although the above-described embodiment, the words of description, andthe drawings refer particularly to a preferred form of the presentinvention, it is apparent that various changes could be made withoutdeparting from the scope and spirit of the invention. Therefore, it isunderstood that the invention is limited solely by the scope of theaccompanying claims.

What is claimed is:

1. Apparatus for gaining access to a sub-merged vessel comprising asnorkel tube which has at one end a hollow upper portion elongated inthe upward direction and being normally free of connection with avessel, and another end that is adapted to be secured to the submergedvessel; a universal joint for connecting the other end of said tube tothe submerged vessel; and passageway means through said tube and saiduniversal joint for communieating between said one end of said snorkeltube and said submerged vessel, and said hollow upper portion having aheight such that it supplies enough buoyancy to support itself andcounterbalance the forces tending to lower the upper part of the snorkeltube.

2. Apparatus according to claim 1, wherein said snorkel tube has a firstportion that is adapted to extend from said joint on an incline relativeto the surface of said water, said upper portion connected at an anglewith said first portion at a point just below the surface of water sothat said upper portion extends upward from the surface of said water.

3. Apparatus according to claim 2, further including a non-buoyant,streamlined bow-shaped plates attached at the waterline to the upperportion of said sn'orkel tube for minimizing wave slap.

4. Apparatus according to claim 1, further including a landing cage,means for pivotally supporting in a vertical plane said cage upon saidsnorkel tube, said cage having a plurality of platforms at differentlevels for receiving personnel and supplies.

5. Apparatus according to claim 1, further including a crane, and meansfor sup-porting said crane upon said snorkel tube for transferringsupplies to said tube.

6. In combination, a hollow body which is adapted to be submerged inwater; a hollow snorkel tube which has one end that is adapted to floatfreely above water; a hollow universal joint for permanently connectingthe other end of said snorkel tube to said hollow body, said upper endbeing upwardly elongated and being normally free of connection with avessel so as'to respond to wave action in heave only in cooperation withthe other parts 6 of said snorkel tube and the universal joint; and ane1evator which is adapted to travel through said snorkel tube and saiduniversal joint for transporting personnel between the floating end ofsaid snorkel tube and the interior of said hollow body.

7. The combination set forth in claim 6, further including a landingcage attached to the free-floating end of said snorkel tube, said cagehaving a plurality of platforms at dilferent levels; and a watertightdoor in said snorkel tube for access to the tube from the top one ofsaid platforms.

8. In combination, a hollow body which is adapted to be submerged inwater; a hollow snorkel tube which has one end that is adapted to floatfreely above water; a hollow universal joint for permanently connectingthe other end of said snorkel tube to said hollow body, said upper endbeing upwardly elongated and being normally free of connection with avessel so as to respond to wave action in heave only in cooperation withthe other parts of said snorkel tube and the universal joint; andnonbuoyant streamlined bow-shaped plates attached at the waterline tosaid snorkel tube at the free-floating end of said tube for minimizingwave slap.

9. A submarine dredge comprising a hollow submersible body, said bodybeing divided into compartments for housing personnel, machinery and asource of power for driving the body along the bottom of a body of waterto dig a trench; a hollow snorkel tube extending from said body on anincline relative to the surface of said body of water, the upper end ofsaid snorkel tube being free-floating upon the Water; a hollow universaljoint for permanently connecting the lower end of said snorkel tube tosaid body for transferring personnel from said snorkel tube to saidsubmersible body, said upper end being upwardly elongated and beingnormally free of connection with a vessel so as to respond to waveaction in heave only in cooperation with the other parts of said snorkeltube and the universal joint, the upper portion of said snorkel tubebeing bent at a point slightly below the surface of said water so thatsaid upper portion extends nearly vertically from said water at a momentwhen the remaining portion of said snorkel tube is inclined by an angleof forty-five degrees relative to the surface of said water; a landingcage; and means for supporting said cage in hinged relationship uponsaid upper portion of said snorkel tube.

10. A submarine dredge as set forth in claim 9, further includingpartially submerged, non-buoyant means supported about said upperportion of said snorkel, said means comprising a pair of bowed platesthat are joined at their ends to form narrow fore and aft edges onopposite sides of said snorkel tube for minimizing wave slap.

References Cited by the Examiner UNITED STATES PATENTS 813,935 2/1906Avery 3756 867,984 10/1907 Lake 3756 1,379,928 5/1921 Lake 37 1,823,9659/1931 Adler 37 1,963,996 6/1934 Lake. 2,390,557 12/1945 Scaife -1ABRAHAM G. STONE, Primary Examiner.

WILLIAM A. SMITH, Examiner.

8. IN COMBINATION, A HOLLOW BODY WHICH IS ADAPTED TO BE SUBMERGED INWATER; A HOLLOW SNORKEL TUBE WHICH HAS ONE END THAT IS ADAPTED TO FLOATFREELY ABOVE WATER; A HOLLOW UNIVERSAL JOINT FOR PERMANENTLY CONNECTINGTHE OTHER END OF SAID SNORKEL TUBE TO SAID HOLLOW BODY, SAID UPPER ENDBEING UPWARDLY ELONGATED AND BEING NORMALLY FREE OF CONNECTION WITH AVESSEL SO AS TO RESPOND TO WAVE ACTION IN HEAVE ONLY IN COOPERATION WITHTHE OTHER PARTS OF SAID SNORKEL TUBE AND THE UNIVERSAL JOINT; ANDNONBUOYANT STREAMLINED BOW-SHAPED PLATES ATTACHED AT THE WATERLINE TOSAID SNORKEL TUBE AT THE FREE-FLOATING END OF SAID TUBE FOR MINIMIZINGWAVE SLAP.
 9. A SUBMARING DREDGE COMPRISING A HOLLOW SUBMERSIBLE BODY,SAID BODY BEING DIVIDED INTO COMPARTMENTS FOR HOUSING PERSONNEL,MACHINERY AND A SOURCE OF POWER FOR DRIVING THE BODY ALONG THE BOTTOM OFA BODY OF WATER TO DIG A TRENCH; A HOLLOW SNORKEL TUBE EXTENDING FROMSAID BODY ON AN INCLINE RELATIVE TO THE SURFACE OF SAID BODY OF WATER,THE UPPER END OF SAID SNORKEL TUBE BEING FREE-FLOATING UPON THE WATER; AHOLLOW UNIVERSAL JOINT FOR PERMANENTLY CONNECTING THE LOWER END OF SAIDSNORKEL TUBE TO SAID BODY FOR TRANSFERRING PERSONNEL FROM SAID SNORKELTUBE TO SAID SUBMERSIBLE BODY, SAID UPPER END BEING UPWARDLY ELONGATEDAND BEING NORMALLY FREE OF CONNECTION WITH A VESSEL SO AS TO RESPOND TOWAVE ACTION IN HEAVE ONLY IN COOPERATION WITH THE OTHER PARTS OF SAIDSNORKEL TUBE AND THE UNIVERSAL JOINT, THE UPPER PORTION OF SAID SNORKELTUBE BEING BENT AT A POINT SLIGHTLY BELOW THE SURFACE OF SAID WATER SOTHAT SAID UPPER PORTION EXTENDS NEARLY VERTICALLY FROM SAID WATER AT AMOMENT WHEN THE REMAINING PORTION OF SAID SNORKEL TUBE IS INCLINED BY ANANGLE OF FORTY-FIVE DEGREES RELATIVE TO THE SURFACE OF SAID WATER; ALANDING CAGE; AND MEANS FOR SUPPORTING SAID CAGE IN HINGED RELATIONSHIPUPON SAID UPPER PORTION OF SAID SNORKEL TUBE.